NOVEMBER 1, 2010

Kubica: Anything can happen at Interlagos

Renault and Robert Kubica is predicting that with the weather an unknown and Interlagos demanding on engine, anything could happen in this weekend's Brazilian GP.

"Brazil is a bit of a strange track and it's really difficult to predict how we will perform," Kubica says. "There is a long straight out of the last corner where the F-duct will give us lots of gain and this is also where the power of the engine will be important. I think that we might have a lottery with the weather because Brazil gets unsettled conditions at this time of year, so it's likely we will have some wet running, as we did in 2009. When it rains the track has very poor grip and you have to be lucky to get the perfect balance with the car.

"It's a difficult track for setting up the car because of the long straight and the uphill sections. You have to choose between top speed or running a lot of downforce and gaining through the corners, so it's very difficult to balance those two things. The track has a bit of everything -- low speed, high speed and it's kind of an old school circuit so there are quite a lot of places where you can gain lap time."

Engineering chief Alan Permane adds: "We set the car up to achieve the optimum lap time, and the way the R30 works with our F-duct should still allow us to achieve good straight-line speeds. It means we can have the downforce in the slow infield corners but still be competitive enough to attack or defend down the straights."

"Finding the sweet spot for the mechanical set-up is a similar story with a balance necessary to deliver a car that works well in the low and high-speed sections. As always, it's the low-speed corners where the most lap time can be found, so it's important that your car has good traction. But, with high-speed corners such as Turn 11, which has an apex speed of 230 km/h, the car needs to be responsive and you can't afford to have a set-up that is too soft."

"As ever, it's about striking the right balance. It's those quick corners with the high g-forces that make Interlagos a tough race physically for the drivers. The forces are highest in turns six and seven where the drivers have to endure 4.5g of lateral acceleration for 4.5 seconds. The anti-clockwise layout also subjects the drivers'' necks to the opposite loadings experienced at clockwise circuits for many of the corners. As a result, don't be surprised to see extra cockpit padding appear on the headrests to help them through 71 laps."

Engine-wise, the long main straight means that power is a critical factor at Interlagos with the cars on full throttle for 16 seconds from the exit of Turn 12 until the braking zone for Turn 1. On top of that, they must cope with the effect of running at altitude because the circuit is around 800m above sea level. "Running at altitude costs an F1 engine around 8% of its power. But, despite losing power, the altitude actually has a positive impact on the engine because the moving parts suffer less. There is less air entering the engine, which means less pressure and less stress on the pistons, conrods, crankshaft and every moving part, which could be a plus to those approaching the end of their engine mileages.